1170 
as the “miner’s inch.” This method 
came from the custom followed by miners 
in appropriating water for the separation 
of gold from the sands and gravel. The 
“miner’s inch” as a unit of measurement 
was well adapted to the mining industry, 
but it seems not well adapted to the 
conditions of agriculture. The “acre- 
foot,” or fraction thereof, as a unit of 
measurement is better than the miner’s 
inch, because it conveys an idea of a 
certain depth of water over a certain 
area of land, as an acre. Almost every 
one is familiar with the expressions in- 
dicating inches in depth. For instance, 
it is known that in the Yakima valley 
there is on the average six inches of pre- 
cipitation per annum, and that this 
classifies the land as arid. They know, 
too, that 15 to 20 inches classifies land 
as semi-arid, and that 30 to 40 inches is 
sufficient for the growing of corn and 
general farming, but no one, unless he 
has had special education in hydraulics, 
knows the relations of a miner’s inch to 
any depth of water covering an acre of 
land. 
The United States Government makes 
its reports of precipitation in terms of 
inches. It also estimates the water de- 
livered to the irrigators under its proj- 
ects in the same way. 
Different canal companies use different 
units of measurement, so that it is diffi- 
cult to express these units in the terms of 
acre-feet, or the miner’s inch. For in- 
stance, in the Yakima valley, Washing- 
ton, are the following ditches with the 
following units of measurement: Naches 
and Cowichie Ditch, one miner’s inch per 
acre; Yakima Valley Canal Co., one inch 
per acre, measured over a wier. The 
Selah Ditch Co. gives two-fifths inches 
per acre, measured under six inches of 
pressure. The Terrace Heights Company 
gives one-third of an inch per acre, 
measured through a meter. The Tieton, 
a government project, gives two and 
seventeen-one-hundredths acre-feet. The 
Moxee Canal Co. gives one cubic foot per 
second for 160 acres of land. The Wash- 
ington Irrigation Company one cubic 
foot per second for 160 acres. The Fow- 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
ler Ditch Co. one cubic foot per second 
for 150 acres. 
The difficulty is for the average per- 
son to know what relations these differ- 
ent standards sustain to each other, or 
to the standard adopted by the govern- 
ment. 
The miner’s inch is not a uniform 
unit for all states. The court of Kittitas 
county, Washington, has defined the 
miner’s inch as “the amount of water 
which will constantly flow through an 
opening one inch square through a plank 
one inch thick in the side of a box in 
which still water is maintained at a con- 
stant depth of four inches above the top 
of the opening.”—Engineering News, 
Nov. 7, 1907. 
In California the measurement is 
taken from center of the opening instead 
of the top. 
Generally throughout the Yakima val- 
ley a miner’s inch is defined as the flow 
of water through an inch aperture under 
six inches of pressure. In some cases 
the aperture is made two inches wide 
and one-half inch long instead of one 
inch square, and this gives less water 
than the inch square because there is 
more friction surface. A continuous flow 
of one miner’s inch is commonly sup- 
posed to be enough to irrigate two acres. 
However, this depends on the character 
of the soil and the character of the crop 
grown. 
It is necessary to distinguish between 
the terms “miner’s inch,” “cubic inch” 
and “acre inch,” as it is to distinguish 
between the terms “second foot,” “cubic 
foot” and “acre foot.’ 
The cubic foot is a cube of one foot on 
every side and contains 1,728 cubic 
inches. It also contains seven and one- 
half gallons. 
The acre-foot is one foot deep over one 
acre of land. 
The second-foot is a cubic foot of water 
discharging from a certain point in one 
second of time. 
The “acre-foot” is a measurement of 
volume, while the term “second-foot” is 
a statement of the rate of flow. A con- 
tinuous flow of one second-foot for 24 
